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Unit-7 Metabolism
Answer: Roots absorb water from the soil, which is transported to leaves for photosynthesis.
Answer: Glucose loses hydrogen and electrons during respiration, meaning it is oxidized.
Answer: At the compensation point the CO2 fixed by photosynthesis equals the CO2 released by respiration.
Answer: Oxygen comes from the splitting of water during the light reaction, not from carbon dioxide.
Answer: Oxidation is the loss of electrons, which may also involve loss of hydrogen or gain of oxygen.
Answer: Enzymes are biological catalysts that speed up biochemical reactions without being used up.
Answer: Reduction is the gain of electrons, which may also involve gain of hydrogen or loss of oxygen.
Answer: Each glucose produces two molecules of NADH when it is split into two pyruvate molecules.
Answer: Catabolic reactions break down molecules and release the energy stored in chemical bonds.
Answer: Water loses electrons and hydrogen during photolysis, so it is oxidized to release oxygen.
Answer: Anabolic reactions build molecules and therefore require an input of energy.
Answer: ATP releases energy when its terminal high-energy phosphate bond is broken.
Answer: In fermentation, such as alcoholic fermentation in yeast, CO2 is released without any oxygen being used.
Answer: Animals release carbon dioxide as a waste product of cellular respiration.
Answer: Enzymes lower the activation energy needed, so reactions occur much faster.
Answer: Glucose is the main respiratory substrate that is broken down to release energy in cells.
Answer: The active site of an enzyme fits only a particular substrate, so each enzyme is specific.
Answer: Aerobic respiration yields about 36 to 38 ATP while fermentation yields only 2 ATP per glucose.
Answer: Minerals are needed for growth, enzyme function and various metabolic activities of plants.
Answer: Temperature, pH and substrate concentration all influence how fast an enzyme works.